Which statement best describes metamorphosis?

• A. It refers only to size increase.
• B. It occurs only in mammals.
• C. It does not involve physiological changes.
• D. It is the change in form and physiology during development.

Answer: (D)

Metamorphosis is the change in form and physiology during development. It isn’t just about getting bigger; it involves a radical reshaping of the body plan and how the body's systems work. For insects, this means that a larva can become an adult with a completely different shape and lifestyle, such as a caterpillar that becomes a butterfly, with major reorganization of tissues like the digestive and sensory systems. In amphibians, tadpoles develop into frogs, gaining legs, losing tails, and shifting from gill-based aquatic life to lung-based terrestrial life. This dynamic transformation—altering both structure and function as development proceeds—is what metamorphosis describes. The other statements miss that broader change: growth alone, or changes limited to mammals, or changes without physiological remodeling, do not capture the full developmental transformation involved.